JP2628333B2 - Air cleaner for engine intake - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an air cleaner for filtering intake air of an engine in a motorcycle or the like.

(Prior Art) An air cleaner provided in a motorcycle generally has the following configuration.

That is, the inside of the cleaner case is an air flow passage, the upstream side communicates with the outside air through an intake hole, and the downstream side communicates with a carburetor through an exhaust hole. And
An element is provided for separating the upstream and downstream sides of the air flow passage.

When the engine is operated and the outside air is sucked through the air cleaner, the outside air is filtered by the element and sent to the carburetor. Since this element is in the form of a sponge and does not have rigidity itself, an element holder is provided to maintain the shape of the element, and the element holder is fixed to the inner wall of the cleaner case.

The cleaner case has a somewhat large cross-sectional area in order to accommodate the element and the element holder in the cleaner case, and thus the cleaner case functions as an expansion chamber. That is, the intake air when the engine is operated is temporarily expanded when passing through the cleaner case, and thereby the intake noise of the engine is reduced.

In the above configuration, in order to more effectively reduce the intake noise, a throttle passage that once narrows the cross-sectional area of a middle portion of the air flow passage in the cleaner case is provided to form two expansion chambers in the cleaner case. That is, it is conceivable that the inside of the cleaner case is made a two-stage expansion system so that the intake air repeats expansion and contraction a plurality of times. Also,
In this case, if the throttle passage is separately provided, the configuration becomes complicated. Therefore, it is conceivable to form the throttle passage in the element holder.

(Problems to be Solved by the Invention) By the way, in order to further reduce the intake noise more effectively, the cross-sectional area of the throttle passage and the length of the passage in the case of the above-described configuration are limited to the specifications of the engine. Each need to be changed. However, since the types of engines mounted on motorcycles are extremely large, forming a cleaner case having a throttle passage of a desired size in order to match the throttle passage to each of these engines makes molding an air cleaner extremely complicated. And the component management becomes complicated.

(Object of the Invention) The present invention has been made in view of the above situation, and effectively reduces the intake noise of the engine, and even in such a case, the number of molding steps and parts management of the air cleaner are easy. The purpose is to be able to.

(Structure of the Invention) A feature of the present invention for achieving the above object is that a throttle passage for once narrowing a cross-sectional area of the air passage in a middle portion from the upstream side to the downstream side of the air passage in the cleaner case. Is formed in the element holder, and the element holder is detachably attached to the cleaner case.

(Operation) The operation of the above configuration is as follows.

Since the forming of the throttle passage 43b is performed using the element holder 42, the inside of the cleaner case 25 can be of a two-stage expansion type with a simple configuration. Therefore, intake noise can be effectively reduced by a rational configuration.

In order to reduce intake noise more effectively,
The throttle passage 43b needs to be changed for each specification of the engine 8. Therefore, in the present invention, the element holder 42 in which the throttle passage 43b is formed is detachable from the cleaner case 25. That is, when the throttle passage 43b is to be changed, it is sufficient to form only the element holder 42 including the throttle passage 43b so as to conform to the specifications of the engine 8 and to attach the same to the cleaner case 25 common to various engines. It has become. Therefore, it is not necessary to form the cleaner case 25 for each of the throttle passages 43b having various dimensions.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a motorcycle, and a front fork 3 supports a front wheel 4 at a front portion of a body frame 2 so as to be steerable. 5 is a handle. A rear arm 6 is pivotally supported at a rear portion of the vehicle body frame 2 to be vertically swingable, and a rear wheel 7 is supported at a swinging end of the rear arm 6.

An engine 8 is mounted on the vehicle body frame 2, and the rear wheel 7 is linked to the engine 8 by a chain transmission means 9. 11 is a fuel tank and 12 is a seat.

A carburetor 13 and an air cleaner 14 are connected to an intake port of the engine 8. When the engine 8 operates, outside air is sucked through the air cleaner 14. After this outside air is filtered by the air cleaner 14, the vaporizer 13
Where it is mixed with the fuel from the fuel tank 11 and the mixture is sent to the engine 8.

The body frame 2 is a double cradle-shaped frame having a steering shaft extension 16 for supporting the front fork 3, and a main frame extending rearward and downward from the steering shaft tube 16.
The main frame 17 supports the fuel tank 11. A down tube extending downward from the steering shaft tube 16 to the rear below the main frame 17.
18 is provided, the main frame 17 and down tube
The rear ends of the 18 are connected by a pair of left and right seat pillar tubes 19.

A pair of left and right seat rails 21 extend rearward and upward from the rear end of the main frame 17, and the seat rails 21 support the seat 12. Further, a pair of left and right back stays 22 are provided under the seat pillar tube 19 and the seat rail 21.
Reinforces the seat rail 21.

And the above seat pillar tube 19, seat rail
The air cleaner 14 is fitted and installed in a triangular space in a side view formed by a back stay 21 and a back stay 22. Further, a side cover 23 extending downward from the seat rail 21 is provided, and a front portion of the side cover 23 covers a rear side surface of the air cleaner 14.

The air cleaner 14 will be described in detail with reference to FIG. 1 and FIGS. 3 to 7.

This air cleaner case 14 is a resin cleaner case
The cleaner case 25 has a case body 26 whose left side is entirely open, and a cover body 27 that entirely covers the left open side of the case body 26. Is detachably screwed to the case body 26 by a first screw 28.

An intake port 29 is formed on the upper surface of the case body 26 as shown in FIG. Further, an inverted L-shaped air introduction pipe 30 extends from the intake port 29 toward the rear of the vehicle body, and the air introduction pipe 30 is located between the left and right seat rails 21 near the lower part of the seat 12. .

On the other hand, an exhaust port 32 is formed on the entire surface of the case main body 26, and a rubber intake pipe 33 connects the exhaust port 32 to the sharp base of the carburetor 13.

When the engine 8 operates, the air 34 flows from the intake port 29 to the exhaust port 32, that is, the inside of the cleaner case 25 has an air flow 35. Further, a partition plate 36 for partitioning the upstream side of the intake port 29 side and the downstream side of the exhaust port 32 side in the cleaner case 25 is formed integrally with the inner wall of the case main body 26. In this case, the left end surface of the partition plate 36 is in close contact with the inner surface of the cover body 27.

The partition plate 36 is formed with a rectangular exhaust port 37 that connects the intake port 29 side in the cleaner case 25 to the exhaust port 32 side. An element 38 made of urethane resin is provided to cover the vent 37. The element 38 includes a trapezoidal box-shaped element main body 39 protruding toward a space on the side of the intake port 29 in the cleaner case 25, and an inner flange 40 integrally formed with a front edge of the element main body 39. .

An element holder 42 for keeping the shape of the element 38 is provided.

This element holder 42 is a rectangular frame-shaped resin substrate
43, which is joined to the front surface of the inner flange 40. A flange 44 is formed on the substrate 43 so as to press against the inner peripheral surface of the inner flange 40. Further, a boss 46 projects from the substrate 43 toward the inside of the element 38, and a bolt 47 is embedded in the boss 46.

A resin frame 49 is fitted into the inner surface of the element 38, and the frame 49 is pressed against the element body 39 and the flange 40, respectively. Further, the front end of the frame 49 is fitted to the flange 44 formed on the substrate 43 so that the frame 49 can be positioned.

A column 50 is integrally formed at the rear of the frame 49, and the column 50 is fitted in a fitting hole 51 formed at the rear of the element body 39. The bolt 47 penetrates the columnar body 50, and a washer 52 is fitted on the bolt 47 and a wing nut 53 is screwed thereto. The above washer
The element 52 is pressed against the rear surface of the element body 39, that is, the element 38 is fastened together with the frame 49 to the substrate 43 by the bolt 47, the washer 52, and the wing nut 53. And
The shape of the element 38 is maintained in a predetermined shape by the substrate 43 and the frame body 49. Also, a handle is on the left side of the board 43
54 are protruding.

An aperture tube 43a is formed integrally with the substrate 43, and the aperture tube 43a protrudes toward the inside of the element.
The inside of the throttle pipe 43a is a throttle passage 43b. The throttle passage 43b extends from the intake port 29 side of the air flow passage 35 to the exhaust port 32b.
It is formed so as to once narrow the cross-sectional area of the halfway to the side.

That is, by forming the throttle passage 43b in the substrate 43, two expansion chambers are created in the cleaner case 25, and the inside of the cleaner case 25 is of a two-stage expansion type.

On the other hand, an opening 55 is formed in the cover body 27 on the left side of the element 38. In addition, a case cover 56 that closes the opening 55 so that it can be opened and closed is provided. The case cover 56 is detachably screwed to the opening edge of the opening 55 with a second screw 57. The opening 55 is formed large enough so that the elements 38 and 42 can be integrally inserted into and removed from the cleaner case 25 therethrough.

When the element 38 and the element holder 42 are taken in and out of the cleaner case 25 through the opening 55, the upper and lower edges of the substrate 43 in the element holder 42 are removably fitted respectively into a pair of upper and lower fitting rails. Grooves 59, 59 are formed on the inner surface side of the vent 37.

When the upper and lower edges of the board 43 are fitted into the fitting grooves 59, 59, the board 43 is pushed toward the inside of the cleaner case 25 by grasping a handle 54, whereby the fitting is performed. The grooves 59, 59 allow the substrate 43 to slide to a predetermined position in the cleaner case 25, that is, to a position where the element 38 entirely covers the ventilation port 37. In addition, the fitting grooves 59, 59 support the element holder 42 at the predetermined positions.

When the substrate 43 reaches a predetermined position in the cleaner case 25 as described above, another fitting groove 60 for removably fitting the right edge, which is the entry end of the substrate 43, is formed on the inner surface of the ventilation hole 37. Formed on the side.

The partition plate 36 including the inner surfaces of the fitting grooves 59 and 60, and the board 4
An elastic seal plate 62 is interposed between the partition plate 3 and the base plate 3 so that the seal between the partition plate 36 and the substrate 43 is reliably achieved. The seal plate 62 is firmly adhered to the substrate 43.

In order to prevent the element holders 42 fitted in the fitting grooves 59, 60 from unexpectedly falling out of the fitting grooves 59, 60, a holding projection 63 is integrally formed on the inner surface of the case cover 56. . That is, the protruding portion of the pressing projection 63 is pressed against the left end of the board 43 fitted in a predetermined position of each of the fitting grooves 59 and 60, thereby preventing the board 43 from falling off.

When the engine 8 is operated and air 34 outside the vehicle is drawn into the cleaner case 25 through the intake port 29, the air 34 passes through the element 38 as shown by the arrow in each drawing. Filtered and then through the outlet 32 the vaporizer 13
Sent to. When the element 38 filters air as described above, the element 38 tends to deform due to the pressure of the air, but this deformation is prevented by the element holder 42. In addition, air 34 is a cleaner case
The expansion and contraction are repeated a plurality of times by passing through the air flow passage 35 including the throttle passage 43b in the inside 25, so that the intake noise is effectively reduced.

Trying to replace the element 38 with another one,
When maintenance such as cleaning is to be performed, first, the second screw 57 is loosened and the case cover 56 is removed as shown by the imaginary line in FIGS. Next, the handle 54 is gripped through the opening 55, and the element holder 42 is pulled out of the cleaner case 25 through the opening 55 together with the element 38. Here, if the wing nut 53 is loosened as shown in FIG. 7, the element 38 can be removed from the element holder 42, and a desired replacement operation can be freely performed.

The operation of attaching the element 38 and the element holder 42 to the inside of the cleaner case 25 may be performed by first integrating them outside the cleaner case 25, and then performing the reverse procedure.

As described above, the element holder 42 is detachable from the cleaner case 25 and the element 38, respectively. Therefore, when the throttle passage 43b is required to conform to the specifications of the engine 8, the throttle passage 43b has a predetermined size. The element 38 may be attached to the element holder 42, and both may be attached to the pre-formed cleaner case 25 common to the various engines 8. That is, it is not necessary to form the cleaner case 25 for each of the throttle passages 43b of various dimensions.

(Effects of the Invention) According to the present invention, the passage for once narrowing the cross-sectional area of the air flow passage is formed in the element holder in the middle from the upstream side to the downstream side of the air flow passage. The inside of the case can be a two-stage expansion system. Therefore, the intake noise of the engine can be effectively reduced by a rational configuration.

Further, in the above configuration, since the element holder in which the throttle passage is formed is detachable from the cleaner case, it is not necessary to form the cleaner case for each of the throttle passages of various dimensions. Therefore, the number of molding steps of the air cleaner and its parts management can be facilitated.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and FIG.
2 is a side view of the motorcycle, FIG. 3 is a partially enlarged view of FIG. 2, FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 1, and FIG. FIG. 6 is a cross-sectional view of the element holder viewed from the same direction as FIG. 3, FIG. 6 is a view taken along line VI-VI of FIG. 5, and FIG. 7 is a development view of the element and the element holder. 8 ... Engine, 14 ... Air cleaner, 25 ... Cleaner case, 35 ... Air flow passage, 38 ... Element, 42 ...
Element holder, 43b …… Throttle passage.

Claims (1)

(57) [Claims] In an air cleaner for engine intake provided with an element for partitioning an upstream side and a downstream side of an air flow passage in a cleaner case and an element holder for maintaining the shape of the element, an upstream side of the air flow passage is provided. An air cleaner for engine intake, in which a throttle passage for once narrowing the cross-sectional area of the air flow passage is formed in the element holder in a middle part from the side to the downstream side, and the element holder is detachably attached to a cleaner case.